diff --git a/crates/loro-internal/src/fuzz/recursive.rs b/crates/loro-internal/src/fuzz/recursive.rs
index f62c345d..32d96355 100644
--- a/crates/loro-internal/src/fuzz/recursive.rs
+++ b/crates/loro-internal/src/fuzz/recursive.rs
@@ -115,13 +115,15 @@ impl Actor {
             Box::new(move |event| {
                 let mut map = map.lock().unwrap();
                 for diff in event.diff.iter() {
+                    println!("diff {:?}", diff);
                     match diff {
                         Diff::Map(map_diff) => {
                             for (key, value) in map_diff.added.iter() {
                                 map.insert(key.to_string(), value.clone());
                             }
                             for key in map_diff.deleted.iter() {
-                                map.remove(&key.to_string());
+                                // map.remove(&key.to_string());
+                                map.insert(key.to_string(), LoroValue::Null);
                             }
                             for (key, value) in map_diff.updated.iter() {
                                 map.insert(key.to_string(), value.new.clone());
@@ -584,7 +586,6 @@ fn assert_value_eq(a: &LoroValue, b: &LoroValue) {
                 if is_empty {
                     continue;
                 }
-
                 assert_value_eq(v, b.get(k).unwrap());
             }
 
@@ -1305,49 +1306,13 @@ mod failed_tests {
     #[test]
     fn list_slice_err() {
         test_multi_sites(
-            5,
-            &mut [
-                Map {
-                    site: 1,
-                    container_idx: 0,
-                    key: 21,
-                    value: Null,
-                },
-                SyncAll,
-                Map {
-                    site: 0,
-                    container_idx: 0,
-                    key: 0,
-                    value: Container(C::Text),
-                },
-                List {
-                    site: 4,
-                    container_idx: 0,
-                    key: 0,
-                    value: I32(1),
-                },
-                Sync { from: 2, to: 4 },
-                Sync { from: 1, to: 2 },
-                Map {
-                    site: 1,
-                    container_idx: 0,
-                    key: 21,
-                    value: Null,
-                },
-                Sync { from: 1, to: 0 },
-                Map {
-                    site: 1,
-                    container_idx: 0,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 0,
-                    container_idx: 0,
-                    key: 251,
-                    value: Container(C::Text),
-                },
-            ],
+            3,
+            &mut [Map {
+                site: 1,
+                container_idx: 0,
+                key: 21,
+                value: Null,
+            }],
         )
     }
 
@@ -1357,35 +1322,56 @@ mod failed_tests {
         minify_error(
             5,
             vec![
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                Text {
+                    site: 149,
+                    container_idx: 149,
+                    pos: 149,
+                    value: 38293,
+                    is_del: true,
                 },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
+                Text {
+                    site: 149,
+                    container_idx: 149,
+                    pos: 149,
+                    value: 38293,
+                    is_del: true,
                 },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
+                Text {
+                    site: 149,
+                    container_idx: 149,
+                    pos: 149,
+                    value: 38293,
+                    is_del: true,
                 },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
+                Text {
+                    site: 149,
+                    container_idx: 149,
+                    pos: 149,
+                    value: 38293,
+                    is_del: true,
                 },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Container(C::Text),
+                Text {
+                    site: 149,
+                    container_idx: 149,
+                    pos: 149,
+                    value: 38293,
+                    is_del: true,
+                },
+                Text {
+                    site: 149,
+                    container_idx: 149,
+                    pos: 149,
+                    value: 38293,
+                    is_del: true,
                 },
                 Map {
                     site: 21,
@@ -1394,371 +1380,439 @@ mod failed_tests {
                     value: Container(C::List),
                 },
                 SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Container(C::List),
+                },
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                SyncAll,
+                List {
+                    site: 64,
+                    container_idx: 64,
+                    key: 64,
+                    value: Null,
+                },
+                List {
+                    site: 64,
+                    container_idx: 64,
+                    key: 64,
+                    value: Null,
+                },
+                List {
+                    site: 64,
+                    container_idx: 64,
+                    key: 64,
+                    value: Null,
+                },
+                List {
+                    site: 64,
+                    container_idx: 64,
+                    key: 64,
+                    value: Container(C::Text),
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 235,
+                    value: Container(C::Text),
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 21,
+                    value: Null,
+                },
+                Map {
+                    site: 21,
+                    container_idx: 21,
+                    key: 64,
+                    value: Null,
+                },
+                List {
+                    site: 64,
+                    container_idx: 64,
+                    key: 64,
+                    value: Null,
+                },
+                List {
+                    site: 64,
+                    container_idx: 64,
+                    key: 64,
+                    value: Null,
+                },
                 Map {
                     site: 0,
                     container_idx: 0,
                     key: 0,
-                    value: Container(C::Text),
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                List {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 41,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Container(C::List),
-                },
-                Sync { from: 191, to: 191 },
-                Sync { from: 21, to: 21 },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 20,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Container(C::List),
-                },
-                SyncAll,
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 255,
-                    key: 255,
-                    value: Null,
-                },
-                Map {
-                    site: 255,
-                    container_idx: 255,
-                    key: 255,
-                    value: Container(C::List),
-                },
-                Sync { from: 197, to: 64 },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                Sync { from: 191, to: 191 },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 5,
-                    container_idx: 5,
-                    key: 5,
-                    value: Null,
-                },
-                Map {
-                    site: 5,
-                    container_idx: 5,
-                    key: 5,
-                    value: Null,
-                },
-                Map {
-                    site: 5,
-                    container_idx: 5,
-                    key: 5,
-                    value: Null,
-                },
-                Map {
-                    site: 5,
-                    container_idx: 5,
-                    key: 5,
-                    value: Null,
-                },
-                Map {
-                    site: 5,
-                    container_idx: 5,
-                    key: 5,
-                    value: Null,
-                },
-                Map {
-                    site: 5,
-                    container_idx: 5,
-                    key: 5,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 61,
-                    container_idx: 61,
-                    key: 61,
-                    value: Null,
-                },
-                List {
-                    site: 61,
-                    container_idx: 61,
-                    key: 61,
-                    value: Null,
-                },
-                List {
-                    site: 61,
-                    container_idx: 61,
-                    key: 61,
-                    value: Null,
-                },
-                List {
-                    site: 61,
-                    container_idx: 61,
-                    key: 61,
-                    value: Null,
-                },
-                List {
-                    site: 61,
-                    container_idx: 61,
-                    key: 61,
-                    value: Null,
-                },
-                Sync { from: 191, to: 46 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 65 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 191 },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 4,
-                    container_idx: 58,
-                    key: 21,
-                    value: Null,
-                },
-                Map {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
-                    value: Null,
-                },
-                List {
-                    site: 64,
-                    container_idx: 1,
+                    site: 0,
+                    container_idx: 0,
                     key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 5,
-                    container_idx: 15,
-                    key: 255,
-                    value: Container(C::Text),
-                },
-                Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
                 Map {
-                    site: 21,
-                    container_idx: 21,
-                    key: 21,
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
-                List {
-                    site: 64,
-                    container_idx: 64,
-                    key: 64,
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
-                List {
-                    site: 64,
-                    container_idx: 66,
-                    key: 64,
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
                     value: Null,
                 },
-                Sync { from: 64, to: 64 },
-                List {
-                    site: 191,
-                    container_idx: 191,
-                    key: 191,
-                    value: Container(C::List),
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
+                },
+                Map {
+                    site: 0,
+                    container_idx: 0,
+                    key: 0,
+                    value: Null,
                 },
-                Sync { from: 191, to: 191 },
-                Sync { from: 191, to: 191 },
             ],
             test_multi_sites,
             normalize,
diff --git a/crates/loro-internal/src/value.rs b/crates/loro-internal/src/value.rs
index 757d0b75..89c0b1ef 100644
--- a/crates/loro-internal/src/value.rs
+++ b/crates/loro-internal/src/value.rs
@@ -282,7 +282,8 @@ impl LoroValue {
                         map.insert(v.0.to_string(), unresolved_to_collection(v.1));
                     }
                     for v in diff.deleted.iter() {
-                        map.remove(v.as_ref());
+                        // map.remove(v.as_ref());
+                        map.insert(v.to_string(), LoroValue::Null);
                     }
                     for (key, value) in diff.updated.iter() {
                         map.insert(key.to_string(), unresolved_to_collection(&value.new));